This invention is directed to an apparatus for maintaining tension on a moving wire, especially a wire that is uncoiled over the axial end of a fixed spool of wire. An apparatus using a mechanical mechanism for automatically maintaining a generally uniform tension on a moving wire as the speed of the wire varies is shown in my U.S. Pat. No. 3,990,652, issued Nov. 9, 1976, which patent is incorporated herein by reference in its entirety. The apparatus shown in my said patent has been commercially successful maintaining tension on uncoiling wires having diameters of approximately 40 A.W.G. and larger. However, when uncoiling wire of a finer gauge, i.e., wire having a diameter of 55 A.W.G. and smaller diameters, the apparatus of my said patent does not respond quickly enough to changes in tension applied to the uncoiling wire because of the high inertia of the mechanical components of the apparatus of my said patent.
Accordingly, an object of this invention is an apparatus for maintaining tension on a moving, uncoiling wire wherein the bending and unbending of the filaments for tensioning the wire respond more quickly to changes in the speed of the uncoiling wire.
Another object of this invention is an apparatus for maintaining tension on a moving, uncoiling wire through the use of an electric motor whose direction of rotation can be rapidly changed.